-But I don't want to go among mad people, Alice remarked.
-Oh, you can't help that, said the Cat, we're all mad here. I'm mad. You're mad.
-How do you know I'm mad? said Alice.
-You must be, said the Cat, or you wouldn't have come here.
-Alice didn't think that proved it at all however, she went on, And how do you know that you're mad?
-To begin with, said the Cat, a dog's not mad. You grant that?
-I suppose so, said Alice.
-Well, then, the Cat went on, you see, a dog growls when it's angry, and wags its tail when it's pleased. Now I growl when I'm pleased, and wag my tail when I'm angry. Therefore I'm mad.